movq %rdi, %rax
	divq %r8

	# expand remainder to 128 for return
	movq %rdx, %rax
	xorl %edx, %edx
	ret

1:
	# crash - only want 64-bit divisor
	xorl %ecx, %ecx
	movl %ecx, 0(%ecx)
	jmp 1b

.section .note.GNU-stack,"",@progbits
EOF

cat >umod-arm64.c <<'EOF'
typedef unsigned int u128 __attribute__((mode(TI)));

static u128 div(u128 x, u128 y, u128 *rp) {

		return ""
	}

	data := make([]byte, 0, 3*4*4)

	var eax, ebx, ecx, edx uint32
	eax, ebx, ecx, edx = cpuid(0x80000002, 0)
	data = appendBytes(data, eax, ebx, ecx, edx)
	eax, ebx, ecx, edx = cpuid(0x80000003, 0)
	data = appendBytes(data, eax, ebx, ecx, edx)
	eax, ebx, ecx, edx = cpuid(0x80000004, 0)
	data = appendBytes(data, eax, ebx, ecx, edx)

	// Trim leading spaces.
	for len(data) > 0 && data[0] == ' ' {

}

type mcontext64 struct {
	es        exceptionstate64
	ss        regs64
	fs        floatstate64
	pad_cgo_0 [4]byte
}

type regs32 struct {
	eax    uint32
	ebx    uint32
	ecx    uint32
	edx    uint32
	edi    uint32
	esi    uint32
	ebp    uint32
	esp    uint32
	ss     uint32
	eflags uint32
	eip    uint32
	cs     uint32
	ds     uint32
	es     uint32

	SizeofIovec           = 0x8
	SizeofMsghdr          = 0x1c
	SizeofCmsghdr         = 0xc
)

const (
	SizeofSockFprog = 0x8
)

type PtraceRegs struct {
	Ebx      int32
	Ecx      int32
	Edx      int32
	Esi      int32
	Edi      int32
	Ebp      int32
	Eax      int32
	Xds      int32
	Xes      int32
	Xfs      int32
	Xgs      int32
	Orig_eax int32
	Eip      int32

			//     MOV off(CX)(TLS*1), AX
			// becomes
			//     mov %gs:off(%ecx), %eax // on i386
			//     mov %fs:off(%rcx), %rax // on amd64
			// which assumes that the correct TLS offset has been loaded into CX (today
			// there is only one TLS variable -- g -- so this is OK). When not building for
			// a shared library the instruction it becomes
			//     mov 0x0(%ecx), %eax // on i386
			//     mov 0x0(%rcx), %rax // on amd64

		{"PtraceRegs", Type, 0},
		{"PtraceRegs.Cs", Field, 0},
		{"PtraceRegs.Ds", Field, 0},
		{"PtraceRegs.Eax", Field, 0},
		{"PtraceRegs.Ebp", Field, 0},
		{"PtraceRegs.Ebx", Field, 0},
		{"PtraceRegs.Ecx", Field, 0},
		{"PtraceRegs.Edi", Field, 0},
		{"PtraceRegs.Edx", Field, 0},
		{"PtraceRegs.Eflags", Field, 0},
		{"PtraceRegs.Eip", Field, 0},
		{"PtraceRegs.Es", Field, 0},